[Role of thrombolytic treatment in thrombosis of valvular prostheses. Apropos of 2 cases and review of the world literature].

The authors report 2 cases of thrombolytic therapy by Urokinase at the dose of 4 500 U/kg/hour, for 24 hours, in patients with thrombosis of a Bjork aortic and Lillehei mitral valve prostheses, and assess the efficacy with a review of the world literature. The first case was a 65 year old woman who received a Bjork No 25 aortic valve prosthesis for aortic regurgitation. Two years later oral anti-vitamin K anticoagulants were replaced by an association of Aspirin-Persantine. She developed acute pulmonary oedema secondary to thrombosis of her valve during the fifth postoperative year. Treatment with Urokinase was successful (4 500 U/kg/hour for 24 hours). The second cases was a 33 year old woman who received a Lillehei No 27 mitral valve prosthesis for mitral regurgitation due to infective endocarditis. Six years later, during a period of apparently ineffective oral anticoagulation, she developed subacute pulmonary oedema due to thrombosis of her prosthesis. Urokinase therapy was successful after 4 hours, but the valve surface area on cardiac catheterisation was decreased and elective reoperation to change the prosthesis was decided upon. Prosthetic valve thrombosis is a serious complication with an operative mortality of 68.6% (35 deaths out of 51 reoperations in the worl literature) whilst the efficacy of thrombolytic therapy would appear to be about 80%. When thrombosis is progressive, the valve has to be changed surgically, but when it is secondary, thrombolytic therapy at least helps the patient survive the acute phase.